Venom "Lite" Alternative for Thrifty Scorpions

[You must be registered and logged in to see this image.]Scorpions don't bother to waste venom killing a victim if they don't have to. Instead, they use a pre-venom that causes extreme pain, resorting to the deadlier version only when necessary, researchers discovered. A team led by entomologist Bruce D Hammock of the University of California, Davis, was researching the possibility of an anti-venom for scorpions when they discovered the stinging creatures produced two kinds of venom. When first confronted by a threat, the scorpion produced a clear liquid on its stinger, Hammock said. The more deadly venom, a thick liquid, "like a milkshake," was produced later, if the threat continued. It's a clever strategy, Hammock explained, because the deadly true venom uses lots of proteins and peptides that are costly for the scorpion to make. Instead, it tries first to get by with a faster acting and more painful toxin that doesn't kill, but is easier to make.

The first scorpion weapon, what Hammock calls a pre-toxin, gets its kick largely from potassium salts that block receptors in animal cells, rapidly causing severe pain. "I was surprised," at the discovery of this pre-toxin, Hammock said. "We spent years looking at the very complex, highly toxic peptide toxin ...and the idea that the scorpion was using salt was a real surprise." It's of more than just biological interest that through evolution the scorpion has developed a way to generate pain and frighten predators and, if necessary, to follow this with a very highly toxic peptide toxin, Hammock said.[You must be registered and logged in to see this image.]Centruroides hentzi